Control for clamshell buckets



March 15, 1949. B, L. ONNGREN 2,464,245

CONTROL FOR CLAMSHELL BUGKETS Filed May 23, 1947 4 Sheets -Sheet 1 "1* ATTORNEY.

B. L. LONNGREN CONTROL FOR CLAMSHELL 'BUGKETS March 15, 1949.

Filed May 23, 1947 4 Sheets-Sheet 2 I INVENTOR,

By W M W ATTORNEY.

March 15, 1949. B. LONNGREN CONTROL FOR CLAMSHELL BUCKETS 4 Sheets-Sheet 3 Filed May 25, 1947 ATTORN E r.

March 15, 1949. B. L.LONNGREN 2,464,245

CONTROL FOR CLAMSHELL BUCKETS Filed May 23, 1947 4 Sheets-Sheet 4 F m gig 330R, if m ATTORN E X Patented Mar. 15, 1949 CONTROL FOR CLAMSHELL BUCKETS Bruno L. Lonngren, South Milwaukee, Wis., assignor to Bucyrus-Erie Company, South Milwaukee, Wis., a corporation of Delaware Application May 23, 1947, Serial No. 749,896 9 Claims. (01. 254185) My invention relates to new and useful improvements in controls for clamshell buckets. This is a continuation-in-part of my application, Serial No. 556,350, filed September 29, 1944, for improvements in Controls for clamshell buckets, which is now abandoned. This case is a continuation as to all common subject-matter, of my aforementioned application, Serial No. 556,350. Clamshell excavators are well known in the art.

In a clamshell excavator, there are two parallel lines, running from the clamshell bucket, over twin sheaves on the end of the boom, to a twodrum winch. One of these lines is called the closing line; the other is called the holding line. When the weight of the bucket hangs on the first-mentioned line, the bucket is shut. When the weight of the bucket hangs on the secondmentioned line, the bucket is open.

In this open position, both lines are paid out, until the bucket lands on the dirt. Then only the closing line is pulled in. This closes the bucket, taking a bite into the dirt. Further pulling-in on this line lifts the bucket full of dirt. The holding drum is manipulated, during hoisting, so as to take up the slack in the holding line. When the bucket has been raised, the holding line is braked, and the closing line is unclutched, and eased off on its brake; with the result that the bucket opens, and discharges its load. This completes the cycle.

The operation of the holding drum during hoisting, above referred to, has in the prior art been of two alternative sorts, as follows. Usually it has been imposed by the operator voluntarily holding the clutch on that drum fully set. But in some improved machines this clutch is provided with a minimum set so that, even if its control lever be moved to full release position, it always imposes a slight drag suflicient for the purpose in question; this eliminates the voluntary control of the holding drum during hoisting.

- The disadvantages inherent in the first of the above-mentioned alternatives are:

l. Operator must watch bucket to know when to engage holding clutch. It is necessary to use markers on ropes when filling bucket out of sight to the operator. Improper engagement will cause loose holding rope with subsequent jar when dumping or a partially closed bucket, which spills material.

2. It takes quite a long time to train the operator to synchronize the two ropes.

3. Meanwhile considerable excessive wear on the ropes and on the brake bands and clutch bands ensues.

4. And, until the operator becomes expert, the bucket will frequently come open, or the holding rope become slack and snarled.

5. Ropes must be of accurate length so that overwinding takes place at the same time on both drums. If not, either the bucket will open, or the holding rope becomes slack and snarled. The rope length varies with buckets and number of parts used in the buckets. If spare amount of rope is used on the closing drum to compensate for replacement in bucket, a corresponding amount must also be installed on the holding drum. Both ropes must be shortened for proper overwinding.

6. The operator must use both hands, thereby having no hand left to control the swinging of the machine.

The disadvantages inherent in the second of the above-mentioned alternatives are:

1. Due to the continuous drag of the holdingline clutch, excessive heat is generated in the drums and band of that clutch, and of the holding-line brake, which results in erratic action thereof.

2. Due to this same heat, the clutch and brake linings wear excessively.

3. The constant drag sometimes starts to lift the bucket when only partially filled.

4. The erratic action mentioned under point 1 above, renders high speed operation impractical, or even impossible.

Accordingly it is the principal object of my invention to provide some quite different system of drums, clutches, controls, etc., of the two-drum winch of a clamshell machine, which system will perform the same cycle described above, but without the employment of a continuously dragging holding-line clutch.

In addition to my principal object, above stated, I hav worked out a number of novel and useful details, which will be readily evident as the description progresses.

My invention consists in the novel parts and in the combination and arrangement thereof, which are defined in the appended claims, and of which one embodiment is exemplified in the accompanying drawings, which are hereinafter particularly described and explained.

Throughout the description, the same reference number is applied to the same member or to similar members.

Figure 1 is a diagonal view in parallel perspective of one variant of my invention.

Figure 2 is a similar view of a slight alteration which may be made in a part of variant No. 1.

Figure 3 is a similar view of a second variant.

Figure 4 is an elevation, partly in section and looking in a direction normal to the axis of the drums, of the first variant of my invention as shown in Figure 1.

Figure 5 is a similar elevation of the second variant of my invention as shown in Figure 3.

The figures are all somewhat conventionalized and diagrammatic, rather than structurally detailed, inasmuch as all the structural parts are well-known in the art.

Turning now to Figure l, we see that my winch, there shown, consists primarily of two drums, II and i2, located on a common drive shaft l3. Each drum is provided with a brake (not shown), which may be of any conventional sort. I! l is the closing drum, which operates the closing line H.

Drive shaft i3 is driven by a gear 55 in any convenient manner from a power-source (not shown).

Integral with drum H is a clutch-drum I6. A cooperating clutch-band l! is dead-ended on gear l5 at B8. The live end IQ of this band. is set, in conventional manner, by a bellcrank 20, pivoted to gear is at 2!, and actuated by link 22, attached at 23 to booster drum 24, which runs free on shaft 53.

Booster band 25, dead-ended on the main frame at 2'6, can be set by hand-lever 27, acting through shaft 28 and a series of unnumbered linkages and bell-cranks. The setting of the booster band retards the booster drum slightly behind the rotation of gear 55, thus setting clutch Il-lfi.

I2 is the holding drum, which operates the holding line 29. This drum is actuated, in identically the same manner as closing drum II namely as follows: Integral with drum i2 is a clutch drum 34. A cooperating clutch band 33 is deadended on spider 35 which is keyed to shaft E3. The live end of this band is set, in conventional manner, by a bell-crank, likewise carried by the spider 35 and pivoted thereon. This bellcrank is actuated by a link attached to booster drum 32 which runs free on shaft l3. Booster band 31, deadended on the main frame, can be set by handlever 3!], acting through a series of unnumbered linkages. The setting of the booster band retards the booster drum slightly behind the rotation of the spider 35, thus setting clutch 33-34. Lever 30 is thus employed to set the holding clutch alone, when it is desired to raise the bucket open and empty.

But there is an additional means for retard ing booster drum 32, and thereby setting clutch 33-34, which means will now be described. Shoe 36 is carried by bellcrank 31, pivoted on the main frame at 38. This bellcrank is actuable by rod 33, in turn actuable by spring 40, in turn actuable by lever 4| keyed to shaft 28.

Whenever lever 21 is swung to set closing clutch !ll6, the pressure of spring 4!! on rod 39 loosely sets shoe 36 on booster drum 32, thus yieldably setting holding clutch 3334, thus causing drum 52 to take up the slack on holding line 29. Yet clutch 3334 is not set hard enough to prevent relative motion of the two lines from closing the bucket.

Turning now to Figure 2, we see a subvariant, identical to that described above, except as follows. Shoe 36a is without lining, and bears upon a portion of band 3|, instead of directly on booster-drum 32.

Turning now to Figure 3, we see a new variant, identical to the first described, variant, except as 4 follows. In place of booster bands 25 and 3|, we have a pair of shoes 25a and 3la. Spring 40 now bears directly on hand-lever 21a, instead of on lever 4|. Several minor changes and reversals have been made in the linkages and bell-crank. Rod 39 now causes bellcrank 42 to bear against pin 33 in the chain of control of booster 3la-32. The operation is similar. Whenever lever 21a is swung to set closing clutch 11-16, the pressure of spring 49 on rod 39 causes bellcrank 42 to bear on pin 43, thus loosely setting shoes 3| a on booster drum 32, thus yieldably setting holding clutch 33-34, with results as described in connection with variant N0. 1.

It is to be understood that other types of clutches with or without the same or other types of boosters could be substituted, without departing from the spirit of my invention.

Having now described and illustrated one form of my invention, I Wish-it to be understood that my invention is not to be limited to the specific form or arrangement of parts herein described and shown.

I claim:

1. In a winch and associated controls, for the operation of a clamshell excavator, the combination of a constantly rotating element; a closing drum; a closing drum clutch, to impart the rota.- tion of the rotating element to the closing drum; a closing drum clutch lever. to actuate the closing drum clutch; a holding drum; a holding drum clutch, to impart the rotation of the rotating element to the holding drum; a holding drum clutch lever, to actuate the holding drum clutch; and a one-way interlock operatively connecting the closing drum clutch lever to the holding drum clutch, in such manner thatmoving said closing drum clutch lever to set or release the closing drum clutch will respectively set or release the 40 holding drum clutch, while leaving the holding drum clutch lever free to operate the holding clutch without operating the closing clutch.

'2. A winch and associated controls, according to claim 1, further characterized by the fact that the interlock is so positioned and proportioned withrespect to the closing drum clutch lever and the holding drum clutch, that the full throw of the closing drum clutch lever will close the holding drum clutch to merely a drag setting, rather than a positive setting.

3. A winch and associated controls, according to claim 1, further characterized by the fact that the interlocking means includes aspring actuated by the closing drum clutch lever, and further in-. cludes an operative connection from the spring to the holding drum clutch.

4. A winch and associated controls, according to claim 1, further characterized by the fact that the holding drum clutch includes a clutch band carried by the rotating element, that there is a booster drum operatively connected to the live end of said band and rotated thereby, that there are two alternative means to arrest the rotation of said booster drum and thereby set the holding drum clutch, that the holding drum clutch lever controls the holding drum clutch through one of these two means, and that the interlock includes the other of these two means. I

5. A winch and associated controls, according to claim 1, further characterized by the fact that the holding drum clutch includes a clutch band carried by the rotating element, that there is a booster drum operatively connected to the live end of said band and rotated thereby that there is a brake band controlled by the holding, drum clutch lever to arrest the rotation of said booster drum and thereby set the holding drum clutch, and that the interlock includes a brake shoe to arrest the rotation of said booster drum and thereby set the holding drum clutch.

6. A Winch and associated controls, according to claim 1, further characterized by the fact that the holdin drum clutch includes a clutch band carried by the rotating element, that there is a booster drum operatively connected to the live end of said band and rotated thereby, that there is one means to arrest the rotation of said booster drum and thereby set the holding drum clutch, that the holding drum clutch lever controls the holding drum clutch through this means, and that the in erlock includes an element to actuate this same '7. A winch and associated controls, according to claim 3., further characterized by the fact that the holding drum clutch includes a clutch band carried by the rotating element, that there is a booster drum operatively connected to the live end of said band and rotated thereby, that there is a brake hand controlled by the holding drum clutch lever to arrest the rotation of said booster drum and thereby set the holding drum clutch, and that the interlock includes means to actuate said brake band by bearing upon a portion thereof.

8. A which associated controls, according to claim 1, further characterized by the fact that there is a booster to set the holding drum clutch, that the holding drum clutch lever controls the holding drum clutch through this booster, and that the interlock includes means to set this booster.

9. In a winch, the combination of: two rope drums, two clutches, one being for each drum; two controls, one to set each clutch; and a onemechanical interlock operatively connecting the control of clutch No. 1 to clutch No. 2, in such manner that said control will always set clutch No. 2 Whenever clutch No. 1 is set, While leavin the control of clutch No. 2 free to set clutch No. 2 without operating clutch No. 1; the elements being so proportioned, adjusted and related, that the setting of clutch N0. 2 by the interlock is a drag setting, rather than a positive setting.

BRUNO L. LONNGREN.

REFERENCES GITED The following references are of record in the of this patent:

Number Name Date 790,765 Turner May 23, 1905 1,401,951 Armstrong Jan. 3, 1922 2,084,449 Neese June 22, 1937 FOREIGN PATENTS Number Country Date 56,974 Denmark Nov. 27, 1939 

